At present, monomers such as alcohols, acids, and esters with a rigid ring structure are single raw materials in the synthesis of high-performance engineering plastics such as polyesters, epoxy resins, polyamides, polyurethanes, and the like. Furan is an important aromatic monomer. However, as a bifunctional reactive group is not present in the structure of furan, furan cannot be directly used for the preparation of high-performance polymers, and the application of furan in the fields of medicine and chemical engineering is also limited.
Since 2,5-disubstituted furan compounds contain a rigid furan ring and a structure of para-diacyl, they can be oxidized or reduced to furan diacids or furan diols, which can be directly used in the preparation of high-performance engineering plastics such as polyesters, epoxy resins, polyamides, polyurethane, and the like. The polymers prepared using furan diacids and furan diols have excellent mechanical properties in terms of strength, modulus, creep resistance, and the like, and simultaneously have higher glass transition temperature and heat distortion temperature. In addition, 2,5-disubstituted furan compounds per se can also be used as chemical raw materials and pharmaceutical intermediates. At present, there are few reports on the synthesis of 2,5-disubstituted furan compounds. Chief among these reports is that a 2,5-diacylfuran compound was synthesized by Uchiyama M et al. with 2-acetylfuran as a raw material [Tetrahedron: Asymmetry, 1997, 8 (20): 3467-3474]. However, this method has the disadvantages of complicated synthesis route, low total yield and high cost, and it is difficult to realize large-scale industrial application.